[Cuis] Curious drawing performance issue

[Phil (list)]

On Sat, 2015-08-15 at 18:41 -0300, Juan Vuletich wrote:
> On 8/15/2015 5:58 PM, Phil (list) wrote:
> > On Sat, 2015-08-15 at 10:24 -0300, Juan Vuletich wrote:
> >> Hi Phil,
> >>
> >> I won't spoil your fun, so instead of explaining the difference between
> >> Squeak and Cuis here, I give you a suggestion: Use the profiler.
> >>
> > Given your comment it sounds like it's by design...
> >
> > OK, so I reverted to an older build to get back the process-based
> > profiler and I can see that Cuis is doing a lot more drawing (work) than
> > Squeak. (duh!) Unfortunately, Cuis/Squeak doesn't provide a lot of
> > tooling to tell me what that work actually is.  What I think I see going
> > on is that Squeak is using the old region-based damage system while Cuis
> > appears to just be bit-blitting the entire frame each time? (I'll hold
> > off jumping up and down for joy until I get confirmation... if that's
> > what's going on, that is FANTASTIC!)
> >
> 
> C'mon! Isn't it obvious in the profiler tree that the problem is using 
> local coordinates and transforming them on each draw?
> 

In the old profiler output (I went back to 2404 to get it), it didn't
jump out at me (the bounds related calls only appear to be <10% of the
time)  It could just be that I'm more dense than usual :-)

I can definitely see how that could cause a problem doing 1000s of local
to global conversions per frame...

> It is possible to optimize it back. It just requires some work.
> 

Fair enough... but I still think that things are generally off
performance-wise with Morphic... (it might just be that we've got a
bunch of fairly unoptimized code similar to what's going on with
BouncingAtomsMorph that will take some time to work through, but things
are definitely feeling slow-ish from a UI standpoint)

> Cheers,
> Juan Vuletich
> 
> >> Cheers,
> >> Juan Vuletich
> >>
> >> On 8/12/2015 6:36 PM, Phil (list) wrote:
> >>> I noticed a while back that something appeared to be going on with Cuis
> >>> drawing performance (at idle on my system Morphic consumes ~20% of VM
> >>> CPU *miniumum* according to ProcessBrowser) and this seems to give an
> >>> indication of what it's currently costing in drawing performance...
> >>>
> >>> After seeing the Squeak 5.0 announcement, I was curious to see roughly
> >>> how much of a speed boost we might be able to expect from Spur down the
> >>> road.  So I decided to look at BouncingAtomsMorph to try to get a rough
> >>> apples-to-apples comparison and was quite surprised: Spur was faster,
> >>> but it was too much faster.  So I dropped back to Squeak 4.5 and it also
> >>> performs much, much better than the Cuis version on the same VM.   Here
> >>> are the numbers I'm seeing using BouncingAtomsMorph with roughly
> >>> comparable (i.e. eyeballed) morph sizes and atom count set to 5000:
> >>> Squeak 5.0 (Spur VM from all-in-one download): 29-31 fps
> >>> Squeak 4.5 (Cog VM 15.25.3390): 24-26 fps
> >>> Cuis 2440 (Cog VM 15.25.3390): 6-8 fps
> >>>
> >>> Granted BouncingAtomsMorph is not 100% identical from a source code
> >>> standpoint but it's not nearly different enough where I'd expect that
> >>> sort of difference.  Is this a platform-specific issue (I'm on Linux) or
> >>> are others noticing drawing issues as well?
> >>>
> >
> >
>